Heat-regulating device for stoves or furnaces



2 sheets shet 1.

(No Model.)

} L. H. FISHER. HEAT REGULATINGDEVIGB FOR STOVBS 0R FURNACES.

No. 509,153. Patented Nov. 21, 1893.

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(No Model.) 2 Sheets-Sheet 2 L. H. FISHER; 7 HEAT REGULATING DEVICE FOR STOVES 0B FURNACES. N0. 509 l53. Patented No. 21, 1893.

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UNITED STATES PATENT OFFICE.

LEWIS H. FISHER, OF WALPOLE, MASSACHUSETTS.

HEAT-REGULATING DEVICE FOR STOVES OR FURNACES.

SPECIFICATION forming part of Letters Patent No. 509,153, dated November 21, 1893.

Application filed May 22, 1893.

To all whom, it may concern:

Be it known that I, LEWIS H. FISHER, of Walpole, in the county of Norfolk and State of Massachusetts, have invented certain new and useful Improvements in Heat-Regulating Devices for Stoves or Furnaces; and I do hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters of reference marked thereon, which form a part of this specification.

My invention relates to that class of heat regulating devices in which the air inlet damper is operated automatically by the expansion or contraction of one or more connections to said damper.

My invention consists generally of such an arrangement of the expansible and other parts which connect the air inlet damper with the stove or furnace, that the operation of said damper is efiected not only by heat radiation or lack of such radiation from the stove or furnace, but which operation is also effected to a sensitive degree by changes of the general surrounding temperature.

My invention consists more particularly of two tubes one inclosed within the other having an annular space between the same and said space closed at its bottom, and said tubes situated within the field of the heat radiation of the stove or furnace, a rod extending through the inner tube and secured at its lower end, and a lever fulcrumed to the upper end of said rod, resting upon the upper edge of the outer tube, and connected with the air inlet damper, whereby the expansion and contraction of the outer tubethe fulcrum rod remaining fixed-will operate the lever to open and close the damper.

My invention also consists in certain features and details, all as hereinafter particularly described.

In the accompanying drawings, Figure 1 illustrates a longitudinal section enlarged of one form of my invention. Fig. 2 shows in side elevation an ordinary parlor stove with the form of apparatus as shown in Fig. 1 applied thereto. Fig. 2* shows in detail a Slightly difierent form of the apparatus as ap- Serial N0-4:75,068- (No model.)

plied to a stove. Fig. 3 is a longitudinal section enlarged of another form of my invention, and partly broken away. Fig. 4 illustrates the apparatus with the modification shown in Fig. 2* as applied to a furnace. Fig. 5 is a detail enlarged of a modification.

Similar letters represent like parts in all the figures.

A is an ordinary parlor stove.

B is the vertical smoke pipe, and O is the smoke pipe connecting with the pipe B and leading to the chimney.

D is the air inlet in the wall of the pipe 0, and E is the damper for opening and closing the same.

Secured to the usual flange or rim F which extends out from the stove near its bottom is a thimble G.

H is a tube formed of two sections a and b, the lower section a being screwed into the thimble G, and said two sections a and 19 separated by a bushing c, and both of the sections with the interposed bushing c united and held together by a coupling d.

I is the interior tube which is inclosed Within the tube H and secured at or near its lower end to the inner surface of the bushing 0.

K is a bar extending across the section a of the tube H and beyond the same, and LM are two parallel rods secured at their lower ends to said bar K, the rod L being secured within the section a and passing 'up and through the inner tube I, and the rod M secured outside of the tube H and extending upward parallel with said tube.

N is a lever resting upon the upper edge of the tube H nearest to the damper E, and with one of its ends spanning the rod L and keptin connection therewith and in proper position, by a vertically adjustable block 6 on said rod bearing upon the upper surface of the lever N. The free end of the leverN freely spans the rod M and extends a short distance beyond the same, and has a transverse bearing groove f on its upper surface beyond the rod M.

O is a second lever also spanning the rod .M above the lever N, and with a transverse bearing edge f resting in the bearing groove f of the lever N, and held in connection therewith and in proper position by an adjusting too block h on the rod M bearing upon the upper surface of the lever O, in a similar manner to the block f bearing upon the lever N. The lever O is connected by a rod P with the crank arm '6 of the damper E. The lower section a of the tube H is provided with an air inlet 70. Instead of the air inlet in the side of the section a, an air inlet tube Z, as shown in Fig. 2*, may be connected with the bottom of section a and extend down to the bottom of the stove.

In order that the regulator may work practically, the two blocks e and 71., should be adjusted when the stove is cold or without fire so that the damper E will be closed and the blocks bearing down upon the levers N and O to hold them firmly and rigidly. Then when the fire is made in the stove, the heat radiating from the same will expand the tube H, and heat the air within the same which will pass out of its top and a partial vacuum will be caused between the tubes H and I. At the same time the warm air below and in the inner tube I will ascend and pass out of the top of said tube, and cold air from the outside will be constantly drawn in through the inlet 70 and take its place. The rod L will therefore be kept practically cool, as the radiation of heat from the stove through the outer tube H, annular chamber with rarefied air, tube I and inclosed cool air, is reduced to a minimum. The outer rod M will also be practically rigid and non-expanding, as it is separated from the stove by the outer air and a portion of the outer tube H. These being the facts, the fulcra of the levers N and O, which are the blocks e and h are always practically fixed after they have been adjusted, and the expansion of the tube H will raise the lever N on its fulcrum e, and said lever N by its bearing edge f will raise the lever O and open the damper E. The hotter the fire, the greater will the tube H expand and the more the damper E will be opened to admit air, check the draft through the stove, and cool off the same. As the stove cools, the tube H will contract, bringing the parts back to their former positions and tending to close the damper E. It will also be found that the tube H is peculiarly sensitive to the changes of temperature in the outer air or in the room where the stove is placed: that on a cold day the tube H will be appreciably cooled so as to contract, and tend to close the damper to remove the check from the draft so that the stove will heat more, and when the weather is warmer and as the temperature of the room more nearly approaches the radiation of heat from the stove, the tendency to contract the tube 11 and close the damper will be less. It will thus be seen that the damper will be operated automatically, not only by the difference of heat radiation from the stove but also by the difference in temperature of the Weather.

In Fig. 3 I have shown the outer rod M and the lever O omitted, but with the lever Q,

which is fulcrumed to the rod Land rests upon the tube H, longer than the lever N in the preceding figures, and connected directly with the rod P. In this construction, the lever Q, through the expansion and contraction of the tube H, will directly operate the damper E only through the one intermediate connection, the rod P. i r

In Fig. 4, I have shown my invention as applied to a furnace A, and in this case, as the radiation from the fire pot is confined to the surrounding hot air chamber R, the two tubes H and I and the interior rod L, except their upper ends are inclosed in such hot air chamher R, the upper ends of said parts passing through the top of said chamber. The outer end of the bar K and the outer rod M, are outside of the chamber R, and an air inlet tube Z extends from the lower part of the tube H to the air shaft S of the furnace. This entire mechanism is supported on the wall of the furnace by a bracket T. The action in this case will be the same as that described in the construction shown in Figs. 1 and 2.

In Fig. 5, instead of the bar K extending through the outer wall of the furnace, and the rod M secured to said bar, the lower end of said rod is provided with a hook m which passes through a hole in the furnace wall, and thus keeps said rod in place. The bracket T in this figure is shown in the form of a coupling in which the section a of the tube H and the air inlet tube Zare screwed.

lVhatI claim as new, and desire to secure by Letters Patent, is

1. In combination with a stove or furnace, a heat regulator consisting of two tubes, one inclosed within the other and having an annular space between the same, and said space closed at its bottom, and said tubes situated within the field of the heat radiation of the stove or furnace, a rod extending through the inner tube and secured at its lower end, and a lever fulcrumed to the upper end of said rod resting upon the upper edge of the outer tube and connected with the air inlet damper, all as and for the purposes set forth.

2. In combination with a stove or furnace, a heat regulator consisting of two tubes, one inclosed Within the other and having an annular space between the same, and said space closed at its bottom, and said tubes situated within the field of the heat radiation of the stove or furnace, two parallel rods one passing through the inner tube and fixed at its lower end, and the other rod situated outside of the outer tube and secured at itslower end, the lever N fulcrumed to the inner rod and resting on the edge of the outer tube, and a lever O fulcrumed to the outer rod, resting on the lever N, and connected with the air inlet damper, all as and for the purposes set forth.

3. In combination with a stove or furnace, a heat regulator consisting of two tubes, one inclosed within the other and having an annular space between the same and said space closed at its bottom, and said tubes situated Y and connected with the air inlet damper, and

a cold air inlet communicating with the lower end of the inner tube, all as and for the purposes set forth.

4. In combination with a stove or furnace, a heat regulator consisting of two tubes, one

, inclosed within the other and having an annular space between the same, and said space closed at its bottom, and said tubes situated within the field of. the heat radiation of the stove or furnace, two parallel rods, one passing through the inner tube and fixed at its lower end, and the other rod situated outside of the outer tube and secured at its lower end, the lever N fulcrumed to the inner rod and resting on the edge of the outer tube, and a lever O fulcrumed to the outer rod resting on the lever N and connected with the air inlet damper, and a cold air inlet communicating with the lower end of the inner tube, all as and for the purposes set forth. r

LEWIS H. FISHER.

Witnesses: LEWIS F. FALES, GEO. A. FALES. 

